Time for tough choices

I have a good friend who is 68 and who lives alone with her middle aged daughter. Her daughter is bedridden with a number of debilitative pain conditions. I do not know all of her health concerns but I know she has had fibromyalgia, rheumatoid arthritis and Crohn’s disease for a long time. The daughter seemed to be managing ok for a while but things have gotten much worse for her over the last couple of years and she is in a lot of pain all of the time and relies on her mother for all of her care. My friend has called an ambulance twice in the last year when things got more than she could handle but the hospital will always just send her back home after stabilizing things because they say there is nothing they can do for her in a hospital that is different than the care she can get at home. This is very sad and it is very hard on a mother to see her daughter like this. But I am more concerned about my friend. She is elderly and not in great health herself but she is on call 24 hours a day to care for her daughter who needs her all of the time. She can no longer attend outside social gatherings because she needs to take care of her daughter and when I go over to visit her at home I can see that the daughter treats her terribly. She yells and screams to get things and calls my friend really horrible names. My friend says she gets like this, abusive, when the pain is bad, which is much of the time. My friend is just overwhelmed but she just doesn’t know what to do. Her daughter has nowhere else to go. I am worried that my friend is in danger from the stress and the constant abuse and it just doesn’t seem right to me. I want to be able to offer her some good advice on what to do but I just can’t think of any to give her. It is hard to feel very sympathetic to the daughter because she is so nasty but I guess she is a lot of pain. I want to help but what can I do and it seems like as much as anyone does to help the daughter she always wants more and more. I don’t think there is any answer here but I thought I would write to you in case you had some professional expertise and advice that was not obvious to me. Thank you for reading my concerns.